.center{
	text-align: center;
}
.flex{
	display: flex;
}
footer{
	position: fixed;
	bottom: 0;
	width: 100%;
	border-top: 1px solid gainsboro;
	background: #fff;
}
footer ul{
	padding-top: 5px;
}
footer li{
	width: 20%;
}
footer .active{
	color: #000;
}
footer li a{
	background-image: url('../img/home-s.png');
	background-size: 22px 24px;
	background-position: top;
	padding-top: 24px;
	display: inline-block;
	background-repeat: no-repeat;
	text-decoration: none;
	color: #777;
}
footer li:nth-of-type(2) a{
	background-image: url('../img/message-n.png');
}
footer li:nth-of-type(3) a{
	background-image: url('../img/publish-n.png');
	background-size: 40px 24px;
	background-position: center;
	display: block;
	padding-top: 40px;
}
footer li:nth-of-type(4) a{
	background-image: url('../img/earn-n.png');
}
footer li:nth-of-type(5) a{
	background-image: url('../img/mine-n.png');
}